audiodecoder: fix invalid timestamps when PLC and delay

Elements inherited from GstAudioDecoder, supporting PLC and introducing
delay produce invalid timestamps. Good example is opusdec with in-band FEC
enabled. After receiving GAP event it delays the audio concealment until
the next buffer arrives. The next buffer will have DISCONT flag set which
will make GstAudioDecoder to reset it's internal state, thus forgetting
the timestamp of GAP event. As a result the concealed audio will have the
timestamp of the next buffer (with DISCONT flag) but not the timestamp
from the event.

1 files changed, 137 insertions, 16 deletions

diff --git a/tests/check/libs/audiodecoder.c b/tests/check/libs/audiodecoder.c
index e33c3f853..cba7a35a3 100644
--- a/tests/check/libs/audiodecoder.c
+++ b/tests/check/libs/audiodecoder.c
@@ -73,6 +73,8 @@ struct _GstAudioDecoderTester
 
   gboolean setoutputformat_on_decoding;
   gboolean output_too_many_frames;
+  gboolean delay_decoding;
+  GstBuffer *prev_buf;
 };
 
 struct _GstAudioDecoderTesterClass
@@ -92,6 +94,11 @@ gst_audio_decoder_tester_start (GstAudioDecoder * dec)
 static gboolean
 gst_audio_decoder_tester_stop (GstAudioDecoder * dec)
 {
+  GstAudioDecoderTester *tester = (GstAudioDecoderTester *)dec;
+  if (tester->prev_buf) {
+    gst_buffer_unref (tester->prev_buf);
+    tester->prev_buf = NULL;
+  }
   return TRUE;
 }
 
@@ -127,10 +134,14 @@ gst_audio_decoder_tester_handle_frame (GstAudioDecoder * dec,
   gint size;
   GstMapInfo map;
   GstBuffer *output_buffer;
+  GstFlowReturn ret = GST_FLOW_OK;
+  gboolean do_plc = gst_audio_decoder_get_plc (dec) &&
+      gst_audio_decoder_get_plc_aware (dec);
 
-  if (buffer == NULL)
+  if (buffer == NULL || (!do_plc && gst_buffer_get_size (buffer) == 0))
     return GST_FLOW_OK;
 
+  gst_buffer_ref (buffer);
   if (tester->setoutputformat_on_decoding) {
     GstCaps *caps;
     GstAudioInfo info;
@@ -143,25 +154,46 @@ gst_audio_decoder_tester_handle_frame (GstAudioDecoder * dec,
 
     gst_audio_decoder_set_output_format (dec, &info);
   }
+  if ((tester->delay_decoding && tester->prev_buf != NULL) ||
+      !tester->delay_decoding) {
+    gsize buf_num = tester->delay_decoding ? 2 : 1;
+    for (gint i = 0; i != buf_num; ++i) {
+      GstBuffer *cur_buf = buf_num == 1 || i != 0 ? buffer : tester->prev_buf;
+      gst_buffer_map (cur_buf, &map, GST_MAP_READ);
+
+      /* the output is SE32LE stereo 44100 Hz */
+      size = 2 * 4;
+      g_assert (size == sizeof (guint64));
+      data = g_malloc0 (size);
+
+      if (map.size) {
+        g_assert_cmpint (map.size, >=, sizeof (guint64));
+        memcpy (data, map.data, sizeof (guint64));
+      }
 
-  gst_buffer_map (buffer, &map, GST_MAP_READ);
-
-  /* the output is SE32LE stereo 44100 Hz */
-  size = 2 * 4;
-  g_assert (size == sizeof (guint64));
-  data = g_malloc0 (size);
-
-  memcpy (data, map.data, sizeof (guint64));
-
-  output_buffer = gst_buffer_new_wrapped (data, size);
+      output_buffer = gst_buffer_new_wrapped (data, size);
 
-  gst_buffer_unmap (buffer, &map);
+      gst_buffer_unmap (cur_buf, &map);
 
-  if (tester->output_too_many_frames) {
-    return gst_audio_decoder_finish_frame (dec, output_buffer, 2);
-  } else {
-    return gst_audio_decoder_finish_frame (dec, output_buffer, 1);
+      if (tester->output_too_many_frames) {
+        ret = gst_audio_decoder_finish_frame (dec, output_buffer, 2);
+      } else {
+        ret = gst_audio_decoder_finish_frame (dec, output_buffer, 1);
+      }
+      if (ret != GST_FLOW_OK)
+        break;
+    }
+    tester->delay_decoding = FALSE;
   }
+
+  if (tester->prev_buf)
+    gst_buffer_unref (tester->prev_buf);
+  tester->prev_buf = NULL;
+  if (tester->delay_decoding)
+    tester->prev_buf = buffer;
+  else
+    gst_buffer_unref (buffer);
+  return ret;
 }
 
 static void
@@ -1010,6 +1042,92 @@ GST_START_TEST (audiodecoder_tag_handling)
 
 GST_END_TEST;
 
+GST_START_TEST (audiodecoder_plc_on_gap_event)
+{
+  /* GstAudioDecoder should not mark the stream DISCOUNT flag when
+  concealed audio eliminate discontinuity. More important it should not
+  mess with the timestamps */
+
+  GstClockTime pts;
+  GstClockTime dur = gst_util_uint64_scale_round (1, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  GstBuffer *buf;
+  GstHarness *h = setup_audiodecodertester (NULL, NULL);
+  gst_audio_decoder_set_plc_aware (GST_AUDIO_DECODER (h->element), TRUE);
+  gst_audio_decoder_set_plc (GST_AUDIO_DECODER (h->element), TRUE);
+
+  pts = gst_util_uint64_scale_round (0, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  gst_harness_push (h, create_test_buffer(0));
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+
+  pts = gst_util_uint64_scale_round (1, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  gst_harness_push_event (h, gst_event_new_gap (pts, dur));
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (!GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+
+  pts = gst_util_uint64_scale_round (2, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  buf = create_test_buffer(2);
+  GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
+  gst_harness_push (h, buf);
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (!GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+  gst_harness_teardown (h);
+}
+GST_END_TEST;
+
+GST_START_TEST (audiodecoder_plc_on_gap_event_with_delay)
+{
+  /* The same thing as in audiodecoder_plc_on_gap_event, but GstAudioDecoder
+  subclass delays the decoding
+  */
+  GstClockTime pts0, pts1;
+  GstClockTime dur = gst_util_uint64_scale_round (1, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  GstBuffer *buf;
+  GstHarness *h = setup_audiodecodertester (NULL, NULL);
+  gst_audio_decoder_set_plc_aware (GST_AUDIO_DECODER (h->element), TRUE);
+  gst_audio_decoder_set_plc (GST_AUDIO_DECODER (h->element), TRUE);
+
+  pts0 = gst_util_uint64_scale_round (0, GST_SECOND, TEST_MSECS_PER_SAMPLE);;
+  gst_harness_push (h, create_test_buffer(0));
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts0, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+
+  ((GstAudioDecoderTester *)h->element)->delay_decoding = TRUE;
+  pts0 = gst_util_uint64_scale_round (1, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  gst_harness_push_event (h, gst_event_new_gap (pts0, dur));
+  fail_unless_equals_int (0, gst_harness_buffers_in_queue (h));
+
+  pts1 = gst_util_uint64_scale_round (2, GST_SECOND, TEST_MSECS_PER_SAMPLE);
+  buf = create_test_buffer(2);
+  GST_BUFFER_FLAG_SET (buf, GST_BUFFER_FLAG_DISCONT);
+  gst_harness_push (h, buf);
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts0, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (!GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+
+  buf = gst_harness_pull (h);
+  fail_unless_equals_int (pts1, GST_BUFFER_PTS (buf));
+  fail_unless_equals_int (dur, GST_BUFFER_DURATION (buf));
+  fail_unless (!GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_DISCONT));
+  gst_buffer_unref (buf);
+  gst_harness_teardown (h);
+}
+GST_END_TEST;
+
 static Suite *
 gst_audiodecoder_suite (void)
 {
@@ -1037,6 +1155,9 @@ gst_audiodecoder_suite (void)
 
   tcase_add_test (tc, audiodecoder_tag_handling);
 
+  tcase_add_test (tc, audiodecoder_plc_on_gap_event);
+  tcase_add_test (tc, audiodecoder_plc_on_gap_event_with_delay);
+
   return s;
 }